Field of the Invention
Aspects of the present invention generally relate to an image forming apparatus and a cartridge group that is detachably attachable to the apparatus body of an image forming apparatus.
In the present specification, the term “image forming apparatus” refers to an apparatus that forms an image on a recording medium. Examples of the image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer and a light-emitting diode (LED) printer), and a facsimile apparatus, each of which uses, for example, an electrophotographic image forming process.
Furthermore, the term “cartridge” refers to a portion of constituent components of the image forming apparatus that is integrated into a cartridge, which is detachably attachable to the apparatus body of the image forming apparatus. The term “cartridge group” refers to a group of a plurality of cartridges mentioned above.
Moreover, the term “image forming apparatus body (apparatus body)” refers to a portion of the image forming apparatus other than the cartridges.
Description of the Related Art
There is known a conventional structure in which an electrophotographic photosensitive member (a photosensitive drum) is supported by two flat surfaces, as discussed in Japanese Patent No. 4110128.
In the structure discussed in Japanese Patent No. 4110128, a photosensitive member supporting device, which supports a photosensitive drum in such a way as to allow the photosensitive drum to rotate, has two contact surfaces which are not parallel to each other and with which the photosensitive drum is kept in contact to be positioned. Then, the configuration is characterized in that the photosensitive drum is urged in such a way as to be in contact with the two contact surfaces by a process unit, such as a charging roller or developing roller, arranged around the photosensitive drum.